Constructional Apraxia in Alzheimer’s Disease: Association with Occipital Lobe Pathology and Accelerated Cognitive Decline
Smith MZ., Esiri MM., Barnetson L., King E., Nagy Z.
The functional impact and progression of occipital lobe pathology in sporadic late onset Alzheimer’s disease (AD) is barely explored. It is accepted that the primary and association visual areas are affected relatively late, in the neocortical stages of AD. We analysed 60 prospectively assessed AD patients in whom global cognitive deterioration and constructional apraxia were evaluated longitudinally using the CAMDEX. Radioactive immunohistochemistry was used to assess the amount of AD-related pathology in Brodmann areas 18 and 17. Braak staging of each case was also carried out. This study showed that in AD patients constructional apraxia is associated with higher expression of hyperphosphorylated tau. Additionally our findings indicate that early constructional apraxia is a predictor of accelerated cognitive decline in AD.